Coated powders having high photostability

ABSTRACT

A coated powder comprises (a) particles, and (b) a coating on the surface of the particles including (1) silica moieties, (2) organo oxysilane moieties selected from the group consisting of mono-organo oxysilane moieties, bi-organo oxysilane moieties and tri-organo oxysilane moieties, and (3) poly(dialkyl)siloxane moieties. The amount by weight in SiO2 equivalents of the organo oxysilane moieties and the silica moieties is at least 0.0625% of the total coated powder weight per m2/g of the specific surface area of the particle to be coated.

BACKGROUND

Particles are added to enhance and modify the properties of manydifferent types of compositions and products. Examples includeultra-violet (UV) light absorbing particles, pigments, colorants,fillers, matting agents, optical diffusing particles, abrasion resistantparticles, viscosity modifiers, magnetic particles and reflectiveparticles.

Particles comprising oxides are particularly suitable as additives,especially particles containing zinc oxides, titanium oxides, siliconoxides, aluminum oxides, iron oxides and/or rare-earth metal oxides.These oxides are thermodynamically stable, are typically unable to reactwith environmentally ubiquitous oxygen, and tend to be less reactivewith water than many other oxides and non-oxide materials. These oxidematerials have been used as pigments and abrasives for centuries.

Particles consisting of certain metal oxides, most notably titaniumoxides, are particularly interesting because they are usually colorlessand transparent to visible light, and provide protection againstexposure to UV light; however, they tend to have poor photostability,caused by the photocatalytic behavior of these oxides. Metal oxidesexposed to UV radiation produce an increase in free radicals. These freeradicals can lead to a de-stabilization of the formulation itself.Furthermore, free radicals may cause the formation of hydroperoxides andother peroxide free radicals known to induce contact dermatitis andsevere allergic reactions. These free radicals also trigger chainreactions resulting in reactive oxygen species (ROS). These highlyreactive derivatives react with cellular components including lipidmembranes and are considered a source of photoaging and skin cancersthat appear later in life. ROS deplete and damage non-enzymatic andenzymatic antioxidant defense systems and cause permanent geneticdamage. Other components in a cosmetic composition may also have lowphotostability, producing additional free radicals on the skin surface.

Coating particles has been found to improve the photostability ofparticles. Coated powders are used to prepare cosmetic compositions forapplication to the skin, such as compositions for protecting skin fromUV radiation (for example, sunscreens).

Particles can be coated to produce coated powders having chemicalstability, photostability, and the ability to form a high weight loadingdispersion with low viscosity. For example, a coating was found thatproduced chemical stability, photostability, and such coated particlesmay be used to form high weight loading dispersions with low viscosity.The coating comprises (1) silica moieties, (2) organo oxysilane moietiesselected from the group consisting of mono-organo oxysilane moieties,bi-organo oxysilane moieties and tri-organo oxysilane moieties, and (3)poly(dialkyl)siloxane moieties. See, for example, U.S. Pat. No.9,139,737.

Antioxidants, often used in cosmetic skin care products, undergooxidation processes under UV radiation, losing their effectiveness. Theaddition of coated powders that block and absorb UV radiation may reducethe oxidation of antioxidants caused by UV radiation. However, many UVblocking particles exhibit photocatalytic activity, such as zinc oxideand titanium oxide, and can lead to the generation of peroxide freeradicals inside a cosmetic composition. This may compromise thestability and efficacy of the antioxidants, due to the prompt reactionbetween the antioxidants and the free radicals or the products producedby the free radicals.

SUMMARY

In a first aspect, the present invention is a coated powder, comprising(a) particles, and (b) a coating, on the surface of the particles,including (1) silica moieties, (2) organo oxysilane moieties selectedfrom the group consisting of mono-organo oxysilane moieties, bi-organooxysilane moieties and tri-organo oxysilane moieties, and (3)poly(dialkyl)siloxane moieties. The amount by weight in SiO₂ equivalentsof the organo oxysilane moieties and the silica moieties is at least0.0625% of the total coated powder weight per m²/g of the specificsurface area of the particle to be coated.

In a second aspect, the present invention is a dispersion, comprising(1) the coated powder, (2) a fluid, and (3) an antioxidant.

In a third aspect, the present invention is a process for producing acoated powder, comprising coating particles with a polymer, bypolymerizing a composition, comprising (i) the particles, (ii) a firstalkoxy silane selected from the group consisting of a tetra-alkoxysilane, a poly(tetra-alkoxy silane), and mixtures thereof, (iii) anorgano alkoxysilane selected from the group consisting of mono-organoalkoxysilane, bi-organo alkoxysilane, tri-organo alkoxysilane, andmixtures thereof, and (iv) a second alkoxy silane selected from thegroup consisting of a poly(dialkyl)siloxane, and mixtures thereof. Theamount by weight in SiO₂ equivalents of the organo oxysilane moietiesand the silica moieties is at least 0.0625% of the total coated powderweight per m₂/g of the specific surface area of the particle to becoated.

In a fourth aspect, the present invention is a coated powder which issuper-photostable.

In a fifth aspect, the present invention is a method of protecting skinfrom light, comprising coating skin with a composition comprising thecoated powder.

In a sixth aspect, the present invention is a method of protectingkeratinous material comprising coating the keratinous material with acomposition comprising the coated powder.

In a seventh aspect, the present invention is a method of protectingskin from light, comprising coating skin with the dispersion.

In an eighth aspect, the present invention is a method of suppressinglipid peroxidation comprising applying to the skin a compositioncomprising the coated powder.

In a ninth aspect, the present invention is a method of preventing orreducing lines and wrinkles on the skin comprising applying to the skina composition comprising the coated powder.

In a tenth aspect, the present invention is a method of preventing lossof elasticity of the skin comprising applying to the skin a compositioncomprising the coated powder.

In an eleventh aspect, the present invention is a method of preventingthinning of the skin comprising applying to the skin a compositioncomprising the coated powder.

Definitions

The term “nanoparticle” means a particle having a particle size of atmost 999 nm. Preferably, a nanoparticle has a particle size of 10 nm to500 nm.

The term “microparticle” means a particle having a particle size of 1 μmto 100 μm.

The term “particle size” means the average diameter of the image of theparticle as viewed by electron microscopy, unless otherwise stated. Theterm “average particle size” means the average of the particle sizes ofa collection of particles.

“High solids content” or “high weight loading” means that thecomposition referred to has at least 50 wt. % solid particles.

“Alkyl” (or alkyl- or alk-) refers to a substituted or unsubstituted,straight, branched or cyclic hydrocarbon chain, preferably containing offrom 1 to 22 carbon atoms. More preferred alkyl groups are lower alkylgroups, for example, alkyl groups containing from 1 to 10 carbon atoms.Preferred cycloalkyls have 3 to 10, preferably 3 to 6, carbon atoms intheir ring structure. Suitable examples of unsubstituted alkyl groupsinclude methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, iso-butyl,tert-butyl, sec-butyl, cyclobutyl, pentyl, cyclopentyl, hexyl, andcyclohexyl.

“Alkenyl” refers to a substituted or unsubstituted, straight, branchedor cyclic, unsaturated hydrocarbon chain that contains at least onedouble bond, and preferably having 2 to 22, more preferably 2 to 6,carbon atoms. Exemplary unsubstituted alkenyl groups include ethenyl (orvinyl) (—CH═CH₂), 1-propenyl, 2-propenyl (or allyl) (—CH₂—CH═CH₂), 1,3-butadienyl (—CH═CHCH═CH₂), 1-butenyl (—CH═CHCH₂CH₃), hexenyl,pentenyl, and 1, 3, 5-hexatrienyl. Preferred cycloalkenyl groups contain5 to 8 carbon atoms and at least one double bond. Examples ofcycloalkenyl groups include cyclohexadienyl, cyclohexenyl,cyclopentenyl, cycloheptenyl, cyclooctenyl, cyclohexadienyl,cycloheptadienyl, and cyclooctatrienyl.

“Alkynyl” refers to a substituted or unsubstituted, straight, branchedor cyclic unsaturated hydrocarbon chain containing at least one triplebond, and preferably having 2 to 22, more preferably 2 to 6, carbonatoms.

“Aryl” refers to any aromatic carbocyclic or heteroaromatic group,preferably having 3 to 10 carbon atoms. The aryl group can be cyclic(such as phenyl (or Ph)) or polycyclic (such as naphthyl) and can beunsubstituted or substituted. Preferred aryl groups include phenyl,naphthyl, furyl, thienyl, pyridyl, indolyl, quinolinyl or isoquinolinyl.

“Heterocyclic radical” refers to a stable, saturated, partiallyunsaturated, or aromatic ring, preferably containing 5 to 10, morepreferably 5 or 6, atoms. The ring can be substituted 1 or more times(preferably 1, 2, 3, 4 or 5 times) with substituent(s). The ring can bemono-, bi- or polycyclic. The heterocyclic group consists of carbonatoms and 1 to 3 heteroatoms independently selected from the groupconsisting of nitrogen, oxygen, and sulfur. The heteroatoms can beprotected or unprotected. Examples of useful heterocyclic groups includesubstituted or unsubstituted acridine, benzathiazoline, benzimidazole,benzofuran, benzothiophene, benzthiazole, benzothiophenyl, carbazole,cinnoline, furan, imidazole, 1H-indazole, indole, isoindole,isoquinoline, isothiazole, morpholine, oxazole, phenazine,phenothiazine, phenoxazine, phthalazine, piperazine, pteridine, purine,pyrazine, pyrazole, pyridazine, pyridine, pyrimidine, pyrrole,quinazoline, quinoline, quinoxaline, thiazole, 1, 3, 4-thiadiazole,thiophene, 1, 3, 5-triazines, and triazole.

“Substituted” means that the moiety contains at least one, preferably1-3 substituent(s). Suitable substituents include hydrogen (H) andhydroxyl (—OH), amino (—NH₂), oxy (—O—), carbonyl (—CO—), thiol, alkyl,alkenyl, alkynyl, alkoxy, halo, nitrile, nitro, aryl, and heterocyclicgroups.

The photostability of titanium dioxide (TiO₂) is measured using the testdescribed below. This test is referred to as the “TiO₂ photostabilitytest.” First a stock solution of 25% resorcinol in ethanol is prepared.8.9 g (±0.01 g) of Finsolv TN and 0.1 g (±0.005 g) of Hostaphat KW 340Dare added to a glass scintillation vial. The capped vial is then placedin a 50° C. oven until the Hostaphat KW 340D dissolves and the solutionis homogeneous (approximately 15 minutes). After removing the vial fromthe oven, 1.0 g (±0.01 g) of coated titanium dioxide powder is added tothe solution. The solution is placed in a sonicator bath and sonicatedfor 15 minutes. 1.0 g (±0.01 g) of the 25% resorcinol in ethanol fromthe first step is added to the scintillation vial and mixed thoroughlyby hand until homogenous. A quartz cuvette is filled with the mixtureand capped with a Teflon lid. The mixture is then tested using a MiltonRoy Color Mate Colorimeter or suitable equivalent colorimeter. Beforetesting the mixture, the colorimeter is calibrated using the white tilecalibration standard. After recording the results of the “pre-irradiatedsample”, the cuvette containing the sample is placed in the QUVweatherometer. The mixtures are then exposed to UV light for exactly 15minutes in a Q-Labs QUV weatherometer using UVB bulbs at 1.23 Wm⁻²s⁻¹ ata constant temperature of 50° C. The test mixtures are then removed forimmediate color measurement in the colorimeter. Photostability may beexpressed as the total color change relative to a standard (ΔE in L*a*b*color space) for a stated UV exposure time. ΔE is calculated from thefollowing expression, as per the CIE76 definition:

ΔE=√{square root over ((L* ₂ −L* ₁)²+(a* ₂ −a* ₁)²+(b* ₂ −b* ₁)²)}

where L*₂, a*₂, and b*₂ are the color coordinates of test mixture postirradiation and where L*₁=99.47, a*₁=−0.16, and b*₁=−0.17 and correspondto the color coordinates of a white reference tile. A coated TiO₂particle is “super-photostable” if ΔE≤15 in the above photostabilitytest.

In order to test the photostability of most compositions other thanTiO₂, such as zinc oxide (ZnO), the following test may be used. Thistest is referred to as the “DPPH photostability test.” First, 0.025g±0.001 g of coated ZnO powder is added to four 50 mL disposable plasticbeakers. 0.0125% DPPH (di(phenyl)-(2,4,6-trinitrophenyl) iminoazanium,also referred to as diphenylpicrylhydrazyl; CAS Number 1898-66-4) isprepared in BCS (ethylene glycol butyl ether) solution. 19.975 g±0.001of 0.0125% DPPH in BCS solution is added to each beaker containingcoated powder. This is mixed thoroughly with a glass stir rod, and eachbeaker is sonicated for 20 seconds, ensuring the powder iswell-dispersed throughout the solution. After sonication, the sample istransferred to a labelled scintillation vial. The pre-irradiated samplesare measured on a calibrated Milton Roy Color Mate Colorimeter orsuitable equivalent colorimeter. After taking the measurements, thesamples are irradiated. The test mixtures are then exposed to UV lightin a Q-Labs QUV weatherometer using a UVA or UVB bulb at 0.35 Wm⁻²s⁻¹ ata constant temperature of 50° C. for exactly 10 minutes. UVA bulbs areused to test particles that filter UVA radiation, and UVB bulbs are usedto test particles that filter UVB radiation. Finally, thepost-irradiated samples are measured on the colorimeter. In this case,photostability following UV exposure is indicated by the persistence ofthe purple color due to the absorption band of the dye at 520 nm.Photostability may be expressed as the total color change relative to astandard (ΔE in L*a*b* color space) for a stated UV exposure time. ΔE iscalculated from the following expression, as per the CIE76 definition:

ΔE=√{square root over ((L* ₂ −L* ₁)²+(a* ₂ −a* ₁)²+(b* ₂ −b* ₁)²)}

where L*₂, a*₂, and b*₂ are the color coordinates of test mixture postirradiation and where L*₁, a*₁, and b*₁ are the initial colorcoordinates of test mixture prior to irradiation. Data is reported asthe average ΔE value of the four samples. A coated particle is“super-photostable” if ΔE≤4.5 in the above photostability test.

The photostability of coated effects pigments is measured using amodified version of the previously described tests. This test isreferred to as the “effects pigments photostability test.” Themodifications were necessary to remove noise in the colorimetrymeasurements induced by the reflectance of the interference pigmentsthemselves in the samples. The test is described below. 0.0125% DPPH(di(phenyl)-(2,4,6-trinitrophenyl) iminoazanium, also referred to asdiphenylpicrylhydrazyl; CAS Number 1898-66-4) is prepared in BCS(ethylene glycol butyl ether) solution. A 20 ml aliquot of the DPPHsolution is transferred to a labelled scintillation vial. This sample ismeasured on the calibrated Milton Roy Color Mate Colorimeter or suitableequivalent colorimeter. Next, 0.025 g±0.001 g of coated effects pigmentpowder is added to four 50 mL disposable plastic beakers. 19.975 g±0.001of 0.0125% DPPH in BCS solution is added to each beaker containingcoated powder. This is mixed thoroughly with a glass stir rod, and eachbeaker is sonicated for 20 seconds, ensuring the powder iswell-dispersed throughout the solution. After sonication, each sample istransferred to a labelled scintillation vial. The test mixtures are thenexposed to UV light in a Q-Labs QUV weatherometer using UVB bulbs at0.35 Wm⁻²s⁻¹ at a constant temperature of 50° C. for exactly 10 minutes.The post-irradiated samples are then filtered through a suitable 1 μmfilter to remove the effects pigments, which can interfere with thecolor measurement. Finally, the filtered post-radiated samples aremeasured on the colorimeter. As before, photostability following UVexposure is indicated by the persistence of the purple color due to theabsorption band of the dye at 520 nm. Photostability may be expressed asthe total color change relative to a standard (ΔE in L*a*b* color space)for a stated UV exposure time. ΔE is calculated from the followingexpression, as per the CIE76 definition:

ΔE=√{square root over ((L* ₂ −L* ₁)²+(a* ₂ −a* ₁)²+(b* ₂ −b* ₁)²)}

where L*₂, a*₂, and b*₂ are the color coordinates of test mixture postirradiation and where L*₁, a*₁, and b*₁ are the initial colorcoordinates of as-made DPPH solution. Data is reported as the average ΔEvalue of the four samples. A coated particle is “super-photostable” ifΔE≤1.15 in the above photostability test, which represents half of theaccepted just noticeable difference value based on CIE76.

Chemical reactivity is measured using the following chemical reactivitytest. A 20 g glass vial is filled with 4.5 g of a stock solution of 5%n-propyl gallate (propyl 3,4,5-trihydroxybenzoate, Aldrich) in isopropylalcohol. One half of a gram of the powder to be evaluated is added tothe glass vial. The glass vial is then agitated, such as by being placedin a bath sonicator for 30 seconds. The mixture is allowed to stand for30 minutes. The sample is then gently mixed using a pipette andtransferred to a cuvette (polycarbonate, polystyrene, or glass) having apath length of 1 cm. The total color change (ΔE) is then measuredagainst a factory white color standard using a Data Color-InternationalSpectraflash SF3000 Colorimeter. Chemical reactivity is expressed as thetotal color change (ΔE). A powder is considered to be chemicallyreactive in application if the chemical reactivity test results in theappearance of a tan color with an accompanying ΔE value greater than 20.

Hydrophobicity is measured using the following hydrophobicity test (thistest is a visible water floatation test commonly used in the cosmeticsindustry, and is described in U.S. Pat. No. 4,454,288). Approximately 30mL of deionized water is placed into a glass jar. Approximately 3.0g±0.30 g of the powder to be tested is added into the glass jar. Theglass jar is tightly sealed, and the sample is swirled around 4 to 5times and vigorously shaken 4 to 5 times, so that intimate contactbetween the water and the powder is achieved. The powder is consideredto be hydrophobic if the powder is buoyant (floating on the surface ofthe water) and water is clear after 15 minutes. The sample is marginallyhydrophobic if the powder is not buoyant but the water is clear after 15minutes, or if the powder is buoyant but the water is not clear after 15minutes.

The fluidity of dispersions of powders is measured using the followingrun-off distance test. Dispersions are produced at 50% solids inethylhexyl benzoate (Finsolv® EB, Innospec). Three drops (75 mg) of thedispersion from a pipette are placed onto a clean glass plate substratewhile the surface is in a horizontal position. The glass substrate isthen held upright for 120 seconds at an angle of 90 degrees to allow thedispersion to flow. The fluidity of the dispersion is expressed as thedistance the dispersion flows from the origin. (This test was only usedduring initial screening; a measured run-off distance of 164±10 mm(reported as standard error) from the origin corresponds to a viscosityof 145±25 cP (reported as standard error) at a shear rate of 20 s⁻¹.). Acoated powder is considered to produce a pourable dispersion if at 50%solids in an ethylhexyl benzoate dispersion it shows a run-off distanceexceeding 100 mm.

The viscosity of dispersions of powders is measured using the followingviscosity test. Dispersions of the powders are prepared incapric/caprylic triglycerides (ALDO® MCT Special KFG, Lonza, CAS Number73398-61-5), ethylhexyl benzoate (Finsolv® EB, Innospec), and linearalkyl benzoate (Finsolv® TN C₁₂₋₁₅ Alkyl Benzoate CAS No.: 68411-27-8)at 50 wt % solids, unless otherwise specified. Viscosity is measured foreach dispersion using a Brookfield DVIII+ Ultra Rheometer with a CP52spindle at 25° C. Measurements are made at shear rates ranging from0.1s⁻¹ to 100 s⁻¹.

The specific surface area of particles is measured in m²/g and isdetermined using the Brunauer-Emmett-Teller (BET) method.

SiO₂ equivalents mean the weight of SiO₂ present after converting allthe silicon in the coating into SiO₂. For example, “the amount byweight, in SiO₂ equivalents”, of the moieties means that all the siliconthat formed the coating is converted to SiO₂ and measured, in order todetermine the percent of each moiety in the coated powder.

Antioxidative power (AP) is measured using the AP method developed byGematria Laboratories (Berlin, Del.). This method offers determinationof the overall antioxidative power of active ingredients, that is, plantextracts, vitamins etc., by monitoring the reducing activity against astable test radical—DPPH with Electron Spin Resonance (ESR)spectroscopy. The AP method utilizes the well-known DPPH method with themajor difference being that both the antioxidative capacity and theantioxidative activity are used to characterize the antioxidant beingtested. For this purpose, different concentrations of the activeingredients are assayed in real time by ESR spectroscopy and thedecrease of the test radical spins is tracked accordingly for each set.With this innovative technique, important kinetic information isadditionally obtained that is completely neglected by most other testsystems. Therefore, both the reaction time and the reduction potentialof the antioxidants contribute to the calculation of the AP.

AP=(RA×N spins)/(w _(c) ×t _(r))

The AP may be described by the equation above, where RA is the constantreduction amplitude (1/e²), N spins is the quantity of reduced freeradicals characterized by free electrons (spins) of DPPH, we is thecharacteristic weight of the antioxidant product and t_(r) is thereduction time (Jung et al., 2006). The resulting AP is expressed inantioxidative units (AU), where 1 AU corresponds to the activity of a 1ppm solution of pure vitamin C (ascorbic acid) as a benchmark. Thismethod allows a rapid and generally applicable technique for themeasurement of the AP across a range of very different classes ofsubstances.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph of the relative percentage of free radicals as the UVirradiation time changes.

FIG. 2 is a graph of the relative AP value after UV irradiation forvarious antioxidants, when in combination with either ZnO having anoctyltriethyloxy silane coating or ZnO having a multifunctional coating.

DETAILED DESCRIPTION

Coated powders of TiO₂ and other selected metal oxides would bedesirable for use in UV protective topical skin compositions, and otherUV protective coatings. However, in order to be commercially desirable,such coated powders need to be (a) photostable, so that they do notsignificantly change color during exposure to UV light; (b) notchemically reactive, so that they do not react with or discolorcompositions during storage; and (c) may be formed into high weightloading dispersions which allow for high SPF values with minimalintroduction of carrier fluid and for cost efficient transport andstorage, but which have a viscosity low enough for easy handling andmixing when preparing consumer compositions.

Although the multifunctional coated powders and high dispersion solidsdescribed in U.S. Pat. No. 9,139,737 is a significant improvement overother existing coated powders, it could be further improved byincreasing the photostability of the coated powders. Furthermore, theaddition of antioxidants to UV protective compositions would reduce theamount of induced free radicals caused by UV radiation exposure.

The present application makes use of coated powders having superiorphotostability, in addition to being chemically stable and having theability to be formed into high weight loading dispersions. The coatedpowders are super-photostable. The coated powder may be used to formcompositions containing antioxidants, and which have a reduced loss ofantioxidants upon exposure to light.

The coated powders are particles coated with a polymer, prepared bypolymerizing a composition containing the particles and at least threecomponents: (A) a first alkoxy silane selected from the group consistingof a tetra-alkoxy silane, a poly(tetra-alkoxy silane), and mixturesthereof, (B) an organo alkoxysilane selected from the group consistingof mono-organo alkoxysilane, bi-organo alkoxysilane, tri-organoalkoxysilane, and mixtures thereof, and (C) a second alkoxy silaneselected from the group consisting of a poly(dialkyl)siloxane, andmixtures thereof.

The coating formed contains moieties corresponding with each of thethree components: (A) silica moieties, (B) organo oxysilane moietiesselected from the group consisting of mono-organo oxysilane moieties,bi-organo oxysilane moieties and tri-organo oxysilane moieties, and (C)poly(dialkyl)siloxane moieties. The coated powders can be used to formdispersions in cosmetically acceptable fluids which have high solids andlow viscosity.

When at least a specific amount of Si (measured as SiO₂ weightequivalents) from all silanes is present in the coating, it has beenfound to yield superior photostability. The compositional range for eachcomponent is based on SiO₂ equivalents. SiO₂ derived from all silanemoieties, that is, silica moieties and organo oxysilane moieties, mustbe greater than or equal to 0.0625% of the total coated powder weightper m²/g of specific surface area of the particle to be coated. Thesilane moieties may be mono, di, tri, and tetrafunctional.

The coated powders can be used to form dispersions in fluids which havehigh solids and low viscosity. The dispersion may be used to preparecosmetic compositions for application to the skin, such as compositionfor protecting skin from UV radiation (for example, sunscreens).Materials considered to be cosmetically acceptable are those which areINCI (International Nomenclature of Cosmetic Ingredients) listed.Examples of cosmetically acceptible fluids are ethylhexyl benzoate (EB),linear alkyl benzoate (LAB), caprylic/capric triglyceride (CCT),squalane, natural product oils, and a variety of silicone fluids.Natural product oils are oils derived from seeds, beans, fruits,flowers, peels, leaves, and the like, including their derivatives.Examples of natural product oils are olive oil and soybean oil.

The coated powder, as well as the dispersions of the coated powder maybe used in a variety of products. They may be added to dermatologicalcompositions to provide UV protection to skin, especially in the case ofTiO₂ and ZnO containing coated powders; the coated powder may also beadded to such compositions as inorganic pigments. The coated powders mayalso be added to shampoos, lotions, gels, hairsprays, aerosol foamcreams or emulsions, for washing, coloring and for styling hair, whilealso providing UV protection to hair. They may be added to paints,sealants and other coatings for wood, plastics and other constructionmaterials; again, UV protection is provided in the case of TiO₂ and ZnOcontaining coated powders. They may also be added to resins, filledpolymers and plastics, and inks. Magnetic fluids may be prepared whenthe metal oxide is magnetic, as in the case of certain iron oxides andrare-earth oxides.

The particles preferably comprise a metal oxide, for example zinc oxide,titanium oxide, silicon oxide, aluminum oxide, iron oxide, bismuthoxide, cerium oxide, rare-earth oxides, infrared light absorbing binaryand ternary mixed metal oxides and mixtures thereof. Examples includeZnO, TiO₂, SiO₂, Al₂O₃, Fe₂O₃, CeO₂, SnO₂, zirconium-cerium oxides,mixed zirconium-rare earth oxides containing cerium, aluminosilicates(including amorphous aluminosilicate, crystalline aluminosilicates, andpumice) and other silicates, aluminum oxides include alumina,aluminosilicates, magnesium aluminum oxides (for example, spinel), zincoxide doped with trivalent metal cations (including aluminum-doped ZnO),antimony-tin oxide (ATO), indium-tin oxide (ITO), fluorine doped tinoxide and doped tungsten oxides. Oxide minerals, such as micas andnatural mineral oxides, may also be used. Metals, other ceramiccompositions including carbides and nitrides and mixtures thereof, aswell as mixtures with oxides, may also be used.

The particles may be effects pigments. The effects pigments aretypically plate or plate-like pigment particles coated with thin layersof a secondary material with a higher refractive index. The compositionsof the underlying plates are typically mica, synthetic mica, silica, oralumina. The coatings are typically titanium dioxide (typically anataseform), iron oxide, or bismuth oxychloride. The color of the pigments iscontrolled by the thickness of the coating layer. The effects pigmentstypically range from 1-100 μm in size. The pigments are also referred toas pearlescent pigments and interference pigments. These materials arecommercially available (XIRALLIC®, PYRISMA®, COLORSTREAM® and IRIODIN®families of products from EMD Performance Materials, MEARLIN®pearlescent pigments from BASF, and SYNCRYSTAL®, SYNAFIL®, MIRAGE®, andVISIONAIRE® effects pigments from Eckart).

Preferably, the particles have a particle size of at most 999 nm,including a particle size of at most 100, 200, and 500 nm, morepreferably a particle size of 10 nm to 500 nm, most preferably aparticle size of 15 nm to 250 nm, such as 20, 30, 40, 50, 60, 70, 80,90, and 100 nm. Preferably, the particles have an average particle sizeof at most 999 nm, including an average particle size of at most 100,200, and 500 nm, more preferably an average particle size of 10 nm to500 nm, most preferably an average particle size of 15 nm to 250 nm,such as 20, 30, 40, 50, 60, 70, 80, 90, and 100 nm. Alternatively, theparticles may have a particle size of 1 μm to 100 μm. Preferably theparticle has an average size of 1 to 10 μm.

The particles may be coated by polymerizing the composition, preferablywithout solvents and with at least some of the composition in the gasphase. The composition includes (A) a first alkoxy silane selected fromthe group consisting of a tetra-alkoxy silane, a poly(tetra-alkoxysilane), and mixtures thereof, (B) an organo alkoxysilane selected fromthe group consisting of mono-organo alkoxysilane, bi-organoalkoxysilane, tri-organo alkoxysilane, and mixtures thereof, and (C) asecond alkoxy silane selected from the group consisting of apoly(dialkyl)siloxane, and mixtures thereof.

Preferably, the first alkoxy silane is present in an amount of 0.1 to 8%by weight of the coated powder, more preferably 0.5% to 7% by weight ofthe coated powder, and most preferably 1.0 to 5% by weight of the coatedpowder, including 1.5, 2, 2.5, 3, 3.5, 4 and 4.5%. Preferably, theorgano alkoxysilane is present in an amount of 0.01 to 5% by weight ofthe coated particles, more preferably 0.05 to 3% by weight of the coatedpowder, and most preferably 0.1 to 1% by weight of the coated powder,including 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 and 0.9%. Preferably,the second alkoxy silane is present in an amount of 0.1 to 10% by weightof the coated powder, more preferably 0.5 to 5% by weight of the coatedpowder, and most preferably 0.75 to 2.5% by weight of the coated powder,including 1.0, 1.25, 1.5, 1.75, 2.0 and 2.25%.

The first alkoxy silane may be a tetra-alkoxy silane, apoly(tetra-alkoxy silane), or mixtures thereof. Tetra-alkoxy silanes arecompounds of the formula (R^(a)O)₄Si, where each R^(a) is an organicgroup which may be the same or different, and each R^(a) is preferablyan alkyl groups having 1 to 22 carbon atoms, more preferably 1 to 10carbon atoms, including 2, 3, 4, 5, 6, 7, 8, and 9 carbon atoms,including methyl, ethyl, and propyl. An example is tetraethoxy silane(TEOS). A poly(tetra-alkoxy silane) is an oligomer of one or moretetra-alkoxy silanes, formed by partial hydrolysis. Preferably thepoly(tetra-alkoxy silane) contains 2 to 14 monomer units, morepreferably 4 to 10 monomer units, including 5, 6, 7, 8, and 9.

The first alkoxy silane may contain silica moieties. Silica moieties areSi(O)₄ groups which bond to 4 atoms, and may also be present in clusterssuch as [OSi(O₂)]_(n)O, where n is 2 to 14, more preferably 4 to 10,including 5, 6, 7, 8 and 9.

The organo alkoxysilane is selected from the group consisting ofmono-organo alkoxysilane, bi-organo alkoxysilane, tri-organoalkoxysilane, and mixtures thereof. The organo alkoxysilane arecompounds of the formula R¹ _(n)Si(OR^(b))_(4-n) where n is 1, 2 or 3.R¹ is an organic group, such as alkyl (for example, linear alkyl,branched alkyl, cyclic alkyl, glycidoxyalkyl, methancryloxyalkyl andaminoalkyl), aryl, vinyl and heteroaryl. Examples of R¹ include methyl,ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl,dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, andoctadecyl. Preferably, R¹ contains 1 to 22 carbon atoms, more preferably1 to 10 carbon atoms, including 2, 3, 4, 5, 6, 7, 8 and 9 carbon atoms.Each R^(b) is an organic group which may be the same or different, andeach R^(b) is preferably an alkyl groups having 1 to 22 carbon atoms,more preferably 1 to 10 carbon atoms, including 2, 3, 4, 5, 6, 7, 8 and9 carbon atoms, including methyl, ethyl, and propyl. An example of anorgano alkoxysilane is triethoxy octylsilane.

The organo alkoxysilane may contain organo oxysilane moieties. Organooxysilane moieties are R¹ _(n)Si(O)_(4-n) groups which bond to “4−n”other atoms, where n is an integer of 1, 2 or 3. R¹ is an organic group,such as alkyl (for example, linear alkyl, branched alkyl, cyclic alkyl,glycidoxyalkyl, methancryloxyalkyl and aminoalkyl), aryl, vinyl andheteroaryl. Examples of R¹ include methyl, ethyl, propyl, butyl, pentyl,hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl,pentadecyl, hexadecyl, heptadecyl, and octadecyl. Preferably, R1contains 1 to 22 carbon atoms, more preferably 1 to 10 carbon atoms,including 2, 3, 4, 5, 6, 7, 8 and 9 carbon atoms. An example of anorgano oxysilane moiety is octylsilane.

The second alkoxy silane is selected from the group consisting of apoly(dialkyl)siloxane, and mixtures thereof. Poly(dialkyl)siloxanes arepreferably oligomers of the formula R^(c)O(SiR² ₂)(R² ₂SiO)_(n)(SiR²₂)OR^(c), where n is an integer of 2 to 14, preferably 4 to 10,including 5, 6, 7, 8 and 9. Each R² is an organic group such as methyl,ethyl, or phenyl, and each R^(c) is an end blocking group such as alkylincluding methyl, ethyl, and propyl to form an alkyloxy group, or H toform a hydroxyl group; hydroxy and alkyloxy groups are both reactivegroups. It is also possible that 1 to 3 of the R² groups are hydroxyland/or alkyloxy groups. R² and R^(c) each independently preferablycontain 1 to 22 carbon atoms, more preferably 1 to 10 carbon atoms,including 2, 3, 4, 5, 6, 7, 8 and 9 carbon atoms. Preferably, thepoly(dialkyl)siloxane is a polydimethylsiloxane or apolydiethylsiloxane. Preferably, the poly(dialkyl)siloxanes have aweight average molecular weight of 200 to 10,000, more preferably 500 to5,000.

The second alkoxy silane the may contain poly(dialkyl)siloxane moieties.Poly(dialkyl)siloxane moieties are O(SiR² ₂)(R² ₂SiO)_(n)(SiR² ₂)O orO(SiR² ₂)(R² ₂SiO)_(n)(SiR² ₂)OR^(c) groups which bond to other atoms,where n is an integer of 2 to 14, preferably 4 to 10, including 5, 6, 7,8, and 9. Each R² is independently an organic group such as methyl,ethyl, or phenyl, and each R^(c) is an end blocking groups such as alkylincluding methyl, ethyl, and propyl to form an alkyloxy group, or H toform a hydroxyl group; hydroxy and alkyloxy groups are both reactivegroups. It is also possible that 1 to 3 of the R² groups are hydroxyland/or alkyloxy groups. R² and R^(c) each independently preferablycontain 1 to 22 carbon atoms, more preferably 1 to 10 carbon atoms,including 2, 3, 4, 5, 6, 7, 8, and 9 carbon atoms. Preferably, thepoly(dialkyl)siloxane moiety is a polydimethylsiloxane moiety or apolydiethylsiloxane moiety.

Typically, the particles and the three components of the composition arethoroughly mixed together, and then placed into a sealed vessel. Thevessel is then evacuated and heated to a temperature where at least twoof components form vapor. The temperature is maintained for sufficienttime to allow polymerization and formation of a coating on theparticles, preferably with continuous mixing during the polymerizationprocess. Carrying out the polymerization reaction for a longer durationallows for a more complete coating of the particle surface. The vesselis then flooded with an inert gas stream which allows the removal ofvolatile by-products such as alcohols and is subsequently allowed tocool to room temperature. The polymer coating formed contains moietiesof each of the three silanes: (1) silica moieties, (2) organo oxysilanemoieties selected from the group consisting of mono-organo oxysilanemoieties, bi-organo oxysilane moieties and tri-organo oxysilanemoieties, and (3) poly(dialkyl)siloxane moieties.

Preferably, the temperature of polymerization is 80° C. to 120° C., morepreferably 90° C. to 110° C., including 92, 94, 96, 98, 100, 102, 104,106, and 108° C. Preferably the amount of time for polymerization is 0.5to 10 hours, more preferably 1 to 6 hours, including 2, 3, 4, and 5hours.

After the polymerization process, the coated powder is heated to 120° C.in order to evaporate any volatile compounds. This drying removes verylittle weight. For purposes of determining the amount of SiO₂equivalents of silicon in the coating, the coated powder is heated to atemperature from 600° C. to 800° C. This process can be carried out in athermogravimetric device or other devices. Combustion to either 600° C.or 800° C. in air will convert all the silicon containing moieties inthe coated powder to SiO₂. The composition of the ignited powder can beconfirmed by a variety of assay methods.

A variety of techniques are available to analyze the coated powder ofthe present invention. The inorganic oxide particles may be dissolvedwith various acids, determining the relative amount of polymer andinorganic oxide, and then the remaining polymer coating may be examinedusing FTIR (Fourier Transform Infrared Spectroscopy) to determine thepresence of different moieties and the relative amounts of each moiety.Other techniques, such as mass spectrometry, TGA (ThermogravimetricAnalysis), or ICP (Inductively Coupled Plasma Spectroscopy) may also beused to establish relative monomer unit ratios. A baseline may beestablished by using a standard of known composition.

The coated powder may also be analyzed by solid state NMR, examining ¹³Cand ²⁹Si NMR signals to determine the presence of different moieties andthe relative amounts of each moiety. Furthermore, the inorganic oxideparticles may be dissolved with various acids, and the remaining polymercoating may be analyzed by NMR, examining ¹³C and ²⁹Si NMR signals todetermine the presence of different moieties and the relative amounts ofeach moiety. A baseline may be established by using a standard of knowncomposition.

The coated powders may be examined for properties using thephotostability test, the chemical reactivity test and the hydrophobicitytest. The coated powders are super-photostable, under the TiO₂photostability test, if the coated powders have a photostability ofΔE≤15, preferably ΔE=1 to 14, including ΔE=2, 3, 4, 5, 6, 7, 8, 9, 10,11, 12 and 13. The coated powders are super-photostable, under the DPPHphotostability test, if the coated powders have a photostability ofΔE≤4.5, preferably ΔE=1 to 4, including ΔE=4.0, 3.5, 3.0, 2.5, 2.0, 1.5and 1.0. The coated powders are super-photostable, under the effectspigments photostability test, if the coated powders have aphotostability of ΔE≤1.15, preferably ΔE=0.5 to 1.0, including 1.05,0.95, 0.85, 0.75, 0.65 and 0.55. Preferably, the coated powders have achemical reactivity of ΔE=0 to 20, more preferably ΔE=0 to 17, mostpreferably ΔE=0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or16. Preferably the coated powders are hydrophobic or marginallyhydrophobic, most preferably hydrophobic.

The coated powder may be used to form dispersions with non-polarliquids, preferably cosmetic oils, such as capric/caprylictriglycerides, linear alkyl benzoate, ethylhexyl benzoate, naturalproduct oils, and silicone oils. Preferably, the dispersions contain atleast 40% by weight coated powder (solids), more preferably at least 50%by weight coated powder (solids), including at least 55% by weightcoated powder (solids), at least 60% by weight coated powder (solids),and at least 65% by weight coated powder (solids), such as 50-65% byweight coated powder (solids), and 55-60% by weight coated powder(solids). Such dispersions may be made by a variety of conventionalmixing processes, including mixing with a rotor-stator machine,planetary mixing, high-pressure homogenizers, ultra-sonic mixing, andmedia milling. An adjunct emulsifier or dispersant may be included inthe dispersions. Examples include tricereareth-4 phosphate (Hostaphat KW340 D; Clariant) at 5-15% by weight of solids.

Surprisingly, high solids dispersions of the coated powders haverelatively low viscosity. Preferably, the viscosity is at most 60,000cP, more preferably at most 30,000 cP, most preferably at most 6,000 cP.Examples include a viscosity of 1,000 to 50,000 cP, and 5,000 to 30,000cP.

One preferred aspect of the present invention includes the addition ofantioxidants to dispersions containing the coated powders. Antioxidantsare oxidized when exposed to UV radiation, leading to a decrease in theantioxidative power. Additionally, zinc oxide and other metal oxides arephoto-reactive, and produce free radicals upon UV radiation exposure.Metal oxides, in combination with antioxidants, would have a greaterloss of AP than the antioxidants alone. However, by combining coatedpowders with antioxidants, the relative AP value of the dispersionremains higher than that of the antioxidants alone. Because the coatedpowders are super-photostable, compositions of coated powders andantioxidants exhibit a synergistic effect together. The antioxidants areable to be effective, because UV radiation is blocked or absorbed by theparticles, preserving the AP value.

Dispersions may contain one or more antioxidant. Antioxidants mayinclude vitamins, antioxidant minerals, antioxidant proteins,antioxidant enzymes and coenzymes, phytonutrients, antioxidant hormones,mycosporine-like amino acids (MAAs), antioxidants derived from marinealgae, and other types of antioxidants. Antioxidants may be watersoluble, fat soluble, or fat and water soluble. Suitable vitaminsinclude vitamin A (including retinoids and carotenoids), vitamin C(ascorbic acid), vitamin E (tocopherols), and vitamin K. Suitableretinoids include retinol, retinoic acid (tretinoin), retinal andretinyl palmitate. Suitable minerals include copper, manganese, iodideand zinc. Suitable enzymes and coenzymes include melatonin, superoxidedismutase, catalase, and glutathione peroxidase. Suitable phytonutrientsinclude carotenoids, flavonoids, phenolic acids, and nonflavonoidphenolics. Suitable carotenoids include alpha-carotene, retinol,astaxanthin, beta-carotene, canthaxanthin, lutein, lycopene, andzeaxanthin. Suitable flavonoids include hindered phenols, apigenin,luteolin, tangeritin, isohamnetin, kaempferol, myricetin,proanthocyanidins, quercetin, eriodictyol, hesperetin, naringenin,catechin, gallocatechin, epicatechin, epigallocatechin, thearubigins,daidzein, genistein, glycitein, resveratrol, pterostilbene, cyanidin,delphinidin, malvidin, pelargonidin, and petunidin. Suitable phenolicacids include phenol, polyphenols, alkylated phenols, and hinderedphenols. Suitable phenols include butylated hydroxyanisole, butylatedhydroxytluene, cannabinoids, capsaicin, carvacrol, cresol, estradiol,eugenol, gallic acid, guaiacol, thymol, tyrosine, and sesamol. Gallicacid includes salts and esters of gallic acid, also known as gallates.Suitable nonflavonoid phenolics include curcumin, flavonolignans,xanthones, and eugenol. Suitable mycosporine-like amino acids (MAAs)include mono-substituted MAAs, such as mycosporine-gycine andmycosporine-taurine, di-substituted MAAs, such as palythenic acid andshinorine, and derivatized MAAs, such as palythine-threonine sulfate andpalythine-threonine glycoside. Examples of suitable MAAs can be found inWada et al. (2015). Antioxidants derived from marine algae includeascorbate, glutathione, phlorotannins, eckol, eckstolonol, prenyltoluquinones, tetraprenyltoluquinols, sargothunbergol A,fucodiphlorethol, terpenoids, phycocyanin, phycocyanobilin, fucoxanthin,phlorotannin, and lutein. Other potential organic antioxidants includebilirubin, citric acid, oxalic acid, phytic acid, n-acetylcysteine, uricacid, green tea, hydoxy-tryrosol, dihydo-quercetin, ubiquinone,glutathione, alpha-lipoic acid, folic acid, ellagic acid, caffeic acid,and phytoestrogens. The antioxidants above also include any salt, esteror acid form of the antioxidant.

Dispersions may contain one or more phyto-extracts. A “phyto-extract” isa substance obtained from a plant. Preferably, the phyto-extract impartsa color. Phyto-extracts must be compatible with non-aqueouscompositions; stable in air; non-staining to skin; non-irritating toskin in the amount used; and non-toxic in the amounts used. Thephyto-extract has a purity level of at least 95%. Examples of suitablephyto-extracts include curcumin, lycopene, beta-carotene, lutein,zeaxanthin, meso-zeaxanthin and anthocyanins. Sources of curcumininclude turmeric. Sources of lycopene include beets, cherries, gojiberries, pink grapefruit, pomegranate, raspberries, red cabbage, redonions, strawberries, tomatoes and watermelon. Sources of beta-caroteneinclude apricots, cantaloupes, carrots, oranges, papayas, peaches,persimmons, pumpkins, summer squash, sweet potatoes, winter squash andyams. Sources of lutein, zeaxanthin, and meso-zeaxanthin includeavocados, broccoli, Brussels sprouts, cabbage, green beans, leafygreens, orange peppers, peas, spinach, yellow corn and zucchini. Sourcesof anthocyanins include beets, black currants, blueberries, cherries,eggplant, figs, grapes, plums, prunes, red cabbage and red currants.Phyto-extracts may be chemically modified by hydrolysis, hydrogenation,esterification or saponification. Phyto-extracts which normally impart acolor may no longer impart a color if they have been chemicallymodified. For example, curcumin imparts a yellow color but tetra-hydrocurcumin, which has been hydrogenated, is colorless.

Dispersions may contain one or more plant bio-extracts. A “plantbio-extract” is a natural extract of a plant that provides a fragranceand may also provide a color. Plant bio-extracts must be compatible withnon-aqueous compositions; stable in air; non-staining to skin;non-irritating to skin in the amounts used; and non-toxic in the amountsused. Synthetic versions of plant bio-extracts are outside the scope ofthe term “plant bio-extract.” Examples of suitable plant bio-extractsinclude arnica extract (Arnica montana), basil extract (Ocimumbasilicum), boswellia extract (Boswellia sacra), calendula extract(Calendula officinalis), chamomile extract (Anthemis nobilis), cinnamonoil (Cinnamomum verum), clove oil (Syzygium aromaticum), coptis extract(Coptis aspleniifolia), echinacea extract (Echinacea purpurea),eucalyptus oil (Eucalyptus occidentalis), ginger root extract (Zingiberofficinale), grape seed extract (Vitis vinefera), green tea extract(Camilla sinensis), guggul resin extract (Commiphora wightii), horsechestnut seed extract (Aesculus hippocastanum), Japanese knotweedextract (Polygonum cuspidatum), licorice extract (Glycyrrhiza glabra),neem leaf extract (Azadirachta indica), olive fruit and olive leafextract (Olea europaea), papaya extract (Carica papaya), Peruvian balsam(Myroxylon balsamum), pineapple extract (Ananas comosus), pomegranateextract (Punica granatum L.), rosemary extract (Rosmarinus officinalis),sage extract (Salvia officinalis), sandalwood extract (Santalum album),turmeric extract (Curcuma longa) and witch hazel extract (Hamamelisjaponica). All the above examples may include different species of thesame genus of plant. For example, witch hazel extract may be obtainedfrom Hamamelis japonica, Hamamelis ovalis, Hamamelis mollis or Hamamelisvirginiana.

The composition optionally includes a phyto-extract. The phyto-extractmay be selected to provide a color. Phyto-extracts that do not impart acolor may also be included in the composition. Phyto-extracts must becompatible with non-aqueous compositions; stable in air; non-staining toskin; non-irritating to skin in the amounts used; and non-toxic in theamounts used. The phyto-extract has a purity level of at least 95%.Examples of suitable phyto-extracts include curcumin, lycopene,beta-carotene, lutein, zeaxanthin, meso-zeaxanthin and anthocyanins.Sources of curcumin include turmeric. Sources of lycopene include beets,cherries, goji berries, pink grapefruit, pomegranate, raspberries, redcabbage, red onions, strawberries, tomatoes and watermelon. Sources ofbeta-carotene include apricots, cantaloupes, carrots, oranges, papayas,peaches, persimmons, pumpkins, summer squash, sweet potatoes, wintersquash and yams. Sources of lutein, zeaxanthin, and meso-zeaxanthininclude avocados, broccoli, Brussels sprouts, cabbage, green beans,leafy greens, orange peppers, peas, spinach, yellow corn and zucchini.Sources of anthocyanins include beets, black currants, blueberries,cherries, eggplant, figs, grapes, plums, prunes, red cabbage and redcurrants. Phyto-extracts may be chemically modified by hydrolysis,hydrogenation, esterification or saponification. Phyto-extracts whichnormally impart a color, such as curcumin, may no longer impart a colorif they have been chemically modified, such as tetra-hydro curcumin. Thecomposition may contain 0.01% to 5.0% phyto-extract, preferably 0.01% to1.0% phyto-extract, including 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%,0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%,0.18%, 0.19% and 0.20% phyto-extract.

The composition optionally includes a plant bio-extract. The plantbio-extract provides a fragrance and may also provide a color. Plantbio-extracts must be compatible with non-aqueous compositions, such asbeing lipophilic or hydrophobic; stable in air; non-staining to skin;non-irritating to skin in the amounts used; and non-toxic in the amountsused. Examples of suitable plant bio-extracts include arnica extract(Arnica montana), basil extract (Ocimum basilicum), boswellia extract(Boswellia sacra), calendula extract (Calendula officinalis), chamomileextract (Anthemis nobilis), cinnamon oil (Cinnamomum verum), clove oil(Syzygium aromaticum), coptis extract (Coptis aspleniifolia), echinaceaextract (Echinacea purpurea), eucalyptus oil (Eucalyptus occidentalis),ginger root extract (Zingiber officinale), grape seed extract (Vitisvinefera), green tea extract (Camilla sinensis), guggul resin extract(Commiphora wightii), horse chestnut seed extract (Aesculushippocastanum), Japanese knotweed extract (Polygonum cuspidatum),licorice extract (Glycyrrhiza glabra), neem leaf extract (Azadirachtaindica), olive fruit and olive leaf extract (Olea europaea), papayaextract (Carica papaya), Peruvian balsam (Myroxylon balsamum), pineappleextract (Ananas comosus), pomegranate extract (Punica granatum L.),rosemary extract (Rosmarinus officinalis), sage extract (Salviaofficinalis), sandalwood extract (Santalum album), turmeric extract(Curcuma longa) and witch hazel extract (Hamamelis japonica). Thedispersion may optionally include extracts from algae species. Thesespecies include Hijikia fusiformis, Spirulina platensis, Aphanizomenon,Spirulina maxima, Sargassum kjellamanianum, S. siliquastrum, Rhodomelaconfervoides, Symphjocladia latiuscula, Kappaphycus alvarezzi,Bottyococcus braunii, Dunaliella saliva, Cystoseira crinite, Eckloniastolonifera, Sargassum thunbergii, S. thunbergii, and Ecklonia cava. Thecomposition may contain 0.10% to 10.0% plant bio-extract, preferably2.0% to 6.0% plant bio-extract, including 2.1%, 2.2%, 2.3%, 2.4%, 2.5%,2.6%, 2.7%, 2.8%, 2.9%, 3.0%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%,3.8%, 3.9% and 4.0% plant bio-extract.

The composition optionally includes an oil-soluble antioxidant. When anantioxidant is present, the antioxidant is different than thephyto-extract. Examples of suitable antioxidants include carotene,catechin, lycopene, resveratrol, Vitamin E or Vitamin A. “Vitamin E” mayrefer to any of the tocopherol or tocotrienol compounds that constitutethe Vitamin E family of compounds, such as alpha-tocopherol andgamma-tocotrienol. The composition may contain 0.01% to 5.0%antioxidant, preferably 0.1% to 3.0% antioxidant, including 0.1%, 0.2%,0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%,1.5%, 1.6%, 1.7%, 1.8%, 1.9% and 2.0% antioxidant.

The dispersion may contain one or more protist extract. A “protistextract” is a substance obtained from a protist. Protists includeeukaryotic organisms that are not animals, plants or fungi. Preferablythe protist extract is a substance that is high in astaxanthins.Examples of suitable protist extracts include plankton extract and algaeextract, particularly red algae extract.

The dispersion may optionally include a protist extract. Preferably theprotist extract is a substance that is high in astaxanthins. Examples ofsuitable protist extracts include plankton extract and algae extract,particularly red algae extract. The dispersion may contain 0.01% to 5.0%protist extract, preferably 0.1% to 3.0% protist extract, including0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%,1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9% and 2.0% protist extract.Cosmetic and dermatological preparations may include cosmeticingredients, auxiliaries and/or additives, for example, co-emulsifiers,fats and waxes, stabilizers, thickeners, biogenic active ingredients,film formers, fragrances, dyes, pearlizing agents, preservatives,pigments, electrolytes, and pH regulators. Suitable co-emulsifiers are,preferably, known W/O and also O/W emulsifiers, for example,polyglycerol esters, sorbitan esters or partially esterified glycerides.Typical examples of fats are glycerides; waxes such as beeswax, paraffinwax or microcrystalline waxes, optionally in combination withhydrophilic waxes. Stabilizers including metal salts of fatty acids, forexample, magnesium, aluminum and/or zinc stearate. Examples ofthickeners include crosslinked polyacrylic acids and derivativesthereof, polysaccharides, such as xanthan gum, guar gum, agar, alginatesand tyloses, carboxymethylcellulose and hydroxyethylcellulose, and fattyalcohols, monoglycerides and fatty acids, polyacrylates, polyvinylalcohol and polyvinylpyrrolidone. Biogenic active ingredients includeplant extracts, protein hydrolyzates and vitamin complexes. Customaryfilm formers include, for example, hydrocolloids, such as chitosan,microcrystalline chitosan or quaternary chitosan, polyvinylpyrrolidone,vinylpyrrolidone/vinyl acetate copolymers, polymers of the acrylic acidseries, and quaternary cellulose derivatives. Examples of preservativesinclude parabens, diazolidinyl urea, iodopropynyl butylcarbamate, andsorbic acid. Examples of pearlizing agents include glycol distearicesters, such as ethylene glycol distearate, fatty acids and fatty acidmonoglycol esters. Dyes which may be used are the substances suitableand approved for cosmetic purposes. Antioxidants, such as amino acids,retinol, flavonoids, polyphenols, vitamin C and tocopherols, may also beincluded.

The cosmetic and dermatological preparations may be in the form of asolution, dispersion or emulsions; for example, sunscreen preparationsmay be in liquid, paste or solid form, for example as water-in-oilcreams, oil-in-water creams and lotions, aerosol foam creams, gels,oils, marking pencils, powders, sprays or alcohol-aqueous lotions.Solvents for these compositions include water; oils, such astriglycerides of capric acid or of caprylic acid, as well as castor oil;fats, waxes and other natural and synthetic fatty substances, esters offatty acids with alcohols of low carbon number, for example withisopropanol, propylene glycol or glycerol, or esters of fatty alcoholswith alkanoic acids of low carbon number or with fatty acids; alcohols,diols or polyols of low carbon number, and ethers thereof, preferablyethanol, isopropanol, propylene glycol, glycerol, ethylene glycol,ethylene glycol monoethyl or monobutyl ether, propylene glycolmonomethyl, monoethyl or monobutyl ether, diethylene glycol monomethylor monoethyl ether. Other examples include isopropyl myristate,isopropyl palmitate, isopropyl stearate, isopropyl oleate, n-butylstearate, diisopropyl adipate, n-hexyl laurate, n-decyl oleate, glycerylstearate, isooctyl stearate, isononyl stearate, isononyl isononanoate,2-ethylhexyl palmitate, 2-ethylhexyl laurate, 2-hexyldecyl stearate,2-octyldodecyl palmitate, oleyl oleate, oleyl erucate, erucyl oleate,and erucyl erucate.

The cosmetic and dermatological preparations may be in the form of solidsticks, and may include natural or synthetic waxes, fatty alcohols orfatty acid esters, liquid oils for example paraffin oils, castor oil,isopropyl myristate, semisolid constituents for example petroleum jelly,lanolin, solid constituents such as beeswax, ceresine andmicrocrystalline waxes and ozocerite, and high-melting waxes includingcarnauba wax and candelilla wax.

Cosmetic preparations may be in the form of gels and preferably includewater, organic thickeners, for example gum arabic, xanthan gum, sodiumalginate, cellulose derivatives such as methylcellulose,hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose,hydroxpropylmethylcellulose and inorganic thickeners, such as aluminumsilicates, for example, bentonites, or a mixture of polyethylene glycoland polyethylene glycol stearate or distearate.

The coated powders and dispersions may also be included in paints,sealants and other coatings, which may also contain binders such aspolyacrylates, polyurethanes, polyalkyds, polyepoxides, polysiloxanes,polyacrylonitriles and/or polyesters. Organic solvents may also bepresent, including ethanol, butyl acetate, ethyl acetate, acetone,butanol, alkanes, methanol, propanol, and pentanol; ethers/acetals suchas tetrahydrofuran and 1,4-dioxane; ketones such as diacetone alcohol,and methyl ethyl ketone; and polyhydric alcohol derivatives such asethylene glycol, propylene glycol, and diethylene glycol or mixturesthereof. These compositions may be used to coat a variety of substrates,including wood, PVC (polyvinyl chloride), plastic, steel, aluminum,zinc, copper, MDF (medium density fiberboard), glass and concrete.Depending on which coated powders are included, the compositions providethe substrate with a coating that may be transparent, UV-resistant,and/or provide greater scratch resistance.

The coated powder and dispersions may be blended with a resin, toprovide an organic polymer composite. Examples of resins include,polyethylene, polypropylene, polystyrene, polyethylene terephthalate, AS(acrylonitrile styrene) resins, ABS (acrylonitrile butadiene styrene)resins, AES (acrylonitrile ethylene styrene) resins, polyvinylidenechloride, methacrylic resins, polyvinyl chloride, polyamides,polycarbonates, polyallyl esters, polyimides, polyacetals, polyetherketones, polyether sulfones, polyphenyl oxides and polyphenylenesulfides, as well as mixtures thereof. Also present in thesecompositions may be coloring agents, fluorescent agents, and additives,such as antioxidants, anti-aging agents, UV-absorbers, lubricants,antistatic agents, surfactants, fillers (the coated powder anddispersions may also act as fillers), plasticizers, stabilizers, blowingagents, expanding agents, electroconductive powder, electroconductiveshort fiber, deodorizing agents, softening agents, thickeners,viscosity-reducing agents, diluents, water-repellent agents,oil-repellent agents, cross-linking agents and curing agents. Theseorganic polymer compositions may be shaped by a variety of techniques,including injection molding, blow molding, extrusion molding, calendermolding, flow molding, compression molding, melt-blown molding, and thespun bond method, whereby shape-imparted products such as fiber, thread,film, sheets, tapes, and injection-molded products and shaped bodiessuch as hollow thread, pipes, and bottles may be produced.Alternatively, the compositions can be subjected to secondary moldingmethods generally applied to thermoplastic resins such as vacuumforming, air pressure forming, and laminate molding.

EXAMPLES

The TiO₂, DPPH and effects pigments photostability tests are customizedtests. The different colorimeter photostability tests are designed toprovide a high level of sensitivity for the various materials. Eachmaterial has different absorption bands and reactivity, so differenttests are needed to accurately measure the resultant color change uponUV radiation exposure. For example, TiO₂ is typically not tested usingDPPH because the TiO₂ is very reactive with the DPPH. The threecolorimeter tests are able to performed quickly and easily by comparingthe color change in a sample to a standard. The testing results can bevalidated by using other testing methods such as Electron Spin Resonance(ESR) spectroscopy.

Example 1

The improved photostability of the coated powder can be measured usingthe TiO₂ photostability test described above. In this test, a passcondition is ΔE≤15 based on experience with spectrophotometric testswhich include selected antioxidants and the ESR-based methods. The datain Table 1 below were based on a constant 40 m²/g (35 nm) rutile phaseTiO₂ particle. Since the coating surface coverage is based on surfaceareas, the mass fractions of the coating components should be scaled tothe specific surface areas of the base particles. Modeling the responsessuggests that the pass/fail condition is traversed when A+B exceeds 2.5%for the case below. Since the common base particle is 40 m²/g in thiscase, the pass/fail boundary is expressed as 0.0625% per m²/g for allparticle types. As shown in Table 1 below, all compositions that meetthe criteria have a ΔE≤15.

TABLE 1 Photostability Test Results SiO₂ from SiO₂ from SiO₂ from ΔEPropylsilane Silicate Polydimethylsiloxane Resorcinol TiO₂ Moieties (A)Moieties (B) Moieties Test A + B Pass/Fail (i) 92.7% 4.7% 0.149% 2.5%14.4 4.9% Pass (ii) 92.2% 2.0% 0.148% 5.7% 16.5 2.2% Fail (iii) 87.1%9.2% 1.835% 1.9% 11.6 11.0% Pass (iv) 92.9% 6.1% 0.150% 0.8% 14.5 6.2%Pass (v) 91.9% 0.7% 0.148% 7.3% 23.9 0.8% Fail (vi) 93.0% 6.1% 0.075%0.8% 14.5 6.2% Pass (vii) 92.0% 0.7% 0.074% 7.3% 21.7 0.7% Fail (viii)92.8% 4.7% 0.075% 2.4% 14.2 4.8% Pass (ix) 92.2% 2.0% 0.074% 5.7% 16.32.1% Fail

The coating components are expressed in terms of weight % of each moietyof total powder (inorganic substrate plus coating) as opposed to thereactant amounts, since the coatings only consist of cross-linkedpolymers of the residues. Not all of the component material will reactwith the particle surface, so it is more accurate to measure the weightpercent of SiO₂ present from each moiety in the coating after ignition.

Example 2

W/O formulations containing physical UV-filters (150 nm zinc oxide) wereanalyzed regarding the amount of UV-inducible free radicals using theradical potential (RP) method below.

A semistable spin probe PCA (2,2,5,5-tetramethyl pyrrolidine N-oxyl) isadded to the test product, the samples are inserted in capillary quartztubes, and the concentration of the spin marker is monitored by ESRspectroscopy before and after defined UV radiation doses. The PCA spinprobe is photostable and resistant to antioxidants, but it promptlyreacts with the UV generated free radicals inside the samples (mainlylipid peroxides and lipidic radicals). The amount of UV generated freeradicals can be quantitatively detected from a calibration curve.

Materials and Methods

A water/EtOH solution of the spin trap (PCA) was added to the W/Oemulsions to obtain a final concentration of 0.01 mM PCA. The samplesare inserted into ESR capillary quartz tubes (40 μL), before the ESRmeasurements and UV irradiation start.

The UV irradiation of the samples was performed with a UV solarsimulator 300 W Oriel (Newport). The irradiances as integrated valueover the spectral ranges were E (UVB=280-320)=23.5 W/m² and E(UVA=320-400 nm)=180 W/m². To test the effect of different UV doses theirradiation time was varied. The emitting intensity is controlled beforeeach measurement. The measurements were performed with a commercial highsensitive X-band bench top Electron Spin Resonance SpectrometerMiniScope MS300, (Magnettech GmbH, Berlin, Germany).

Results and Discussion

The amount of UV-induced free radicals inside cosmetic formulations wasmeasured. Knowing the concentration of the spin trap PCA within thesample (0.01 mM), the amount of reduced PCA can be calculated. Since oneelectron is needed to reduce 1 molecule of PCA, the radicalconcentration inside the sample can be calculated using a calibrationcurve. The percent of induced free radicals corresponding to eachproduct is shown in Table 2.

TABLE 2 Relative and Absolute Amounts of Free Radicals % of inducedinduced free Product free radicals radicals (μM) ±sd placebo(comparative) 8.6 0.857 0.79 ZnO (comparative) 24.6 2.462 0.28 ZnO +Octyltriethoxysilane coating 27.4 2.743 0.06 (comparative) ZnO +Multifunctional coating 2.8 0.284 0.27

Two different coating technologies for ZnO coating were tested. Withrespect to the uncoated material, no protective effect was seen in thesample having a coating formed from octyltriethoxysilane. On thecontrary, radical formation was reduced to less than 3% in the samplecontaining ZnO with a multifunctional coating. The change in thepercentage of induced free radicals for the different products as the UVirradiation time changes is shown in FIG. 1. The materials and monomersused to form the multifunctional coating components are shown in Table3, below.

TABLE 3 Components of Multifunctional coating Component % by WeightPropylsilane moieties 5.5% Silicate moieties (from tetrafunctionalsilane) 0.8% Polydimethyl siloxane moieties 0.9% 150 nm ZnO 92.8%

Example 3

In the presented test design, different photo-unstable antioxidants havebeen added to formulations containing ZnO with different coatingtechnologies. The antioxidative activity of these formulations wasdetermined, using the AP method, before and after UV irradiation of theformulations.

The antioxidants have been chosen according to the following criteria:(1) The antioxidants used are suitable to be used in cosmeticformulations, and (2) The 5 raw materials represent different classes ofantioxidants having different molecular mechanism, hydrophilic andlipophilic character. The final concentrations of each antioxidants werechosen based on the antioxidative capacity of the raw materials. Allconcentrations stayed within the range of recommended use, based onEU-guidelines.

Antioxidants are oxidized when exposed to UV radiation, leading to adecrease in the antioxidative power (AP). Table 4 below, shows that theAP decreases upon exposure to UV radiation. The “after UV” columninformation was collected after 10 minutes of UV radiation exposure,which is equivalent to 2.4 MEDs (minimal erythermal doses). Whileantioxidants would reduce the number of free radicals, exposure to UVradiation greatly reduces the AP of antioxidants.

TABLE 4 Loss of AP with UV Radiation Exposure. In the placebo Before UVAfter UV AP (%) AP (%) Ascorbic acid 0.05% 100 8 Tocopherol 0.5% 100 0Green tea 0.05% 100 2 Hydroxytyrosol 0.05% 100 42 Quercetin 0.1% 100 74

Materials and Methods

The measurements of the antioxidant capacity and reactivity wereperformed by using ESR spectroscopy. Since this spectroscopic techniqueis able to quantify free radicals and since it is applicable to opaque,viscous, and colored samples, it is particular suitable for the analysisof antioxidants in cosmetic products. The measurements were performedwith the X-band ESR spectrometer Miniscope MS 300 (Magnettech, Germany)and the following technical parameters: 60 G sweep width, 100 Gain, 1 Gmodulation amplitude, 7 mW attenuation, 3365 G central field, 0.14 sectime constant. The Antioxidative Power (AP) is a parameter able toquantify both the reaction capacity and velocity of antioxidants. Thetest radical DPPH (2,2-diphenyl-1-picryl-hydrazyl, Sigma-Aldrich,Munich, Germany) is used as a detector molecule. At least 3concentrations of the test sample were prepared and added to DPPH toobtain an initial radical concentration of 0.1 mM. The signal intensitydecay of each concentration of the test samples is recorded at differenttime intervals during the reaction until saturation is reached and allantioxidant active molecules have reacted with the test radical.

From these intensities, a first order kinetic was obtained for eachconcentration set. The kinetic parameters are used to calculate thereaction time (t_(r)) and the static parameters are used to calculatethe characteristic weight (w_(c)).

For a direct comparison of different antioxidants, the AP method isstandardized to the activity of vitamin C (ascorbic acid, supplied bySigma-Aldrich, Munich, Germany, at the highest grade of purity). Theantioxidative activity of a solution of 1 ppm vitamin C is defined as anantioxidative unit (AU). For each formulation, the AP value before andafter exposure to UV radiation was determined.

Results

300 mg of each formulation was applied on a glass plate (microscopeslide) and exposed to UV radiation using a sun simulator (Heinle SOL 2sun simulator) for 10 minutes (22.7 J/cm²). The products are collectedfrom the slides and the AP is determined. The weight of the samplesbefore and after UV exposure was controlled for each sample. The weightloss due to water evaporation was below 5% for all of the samples.

The formulations containing ZnO, independently from the coating, showeda protective effect during the relatively low UV irradiation. Therefore,the products containing 10% of ZnO were diluted by a factor 4 using theplacebo. The following experiments were therefore conducted withformulations containing 2.5% of ZnO. The formulations containing 2.5%ZnO showed photoprotective effects for most of the antioxidants used,due to the UV-scattering effect.

Nevertheless, there is a significant difference between the two ZnOpreparations: The antioxidants were less stable in the formulationscontaining ZnO having a coating formed from octyltriethoxysilane,compared to the ZnO having a multifunctional coating.

The generation of UV-inducible free radicals was evaluated for the twoZnO-containing formulas (see Example 2 above). The particles having themultifunctional coating showed no radical generation, whereas in theformula containing ZnO having a coating formed from octyltriethoxysilane, a high photo-catalytic activity was observed. Thisphotocatalytic activity will lead to the generation of hydroperoxides,mainly hydroxyl radicals, which promptly react with the antioxidants,leading to an oxidation and a consequent decrease in their AP. FIG. 2shows the relative AP values after UV irradiation are greater for themultifunctional coating than for the coating formed from octyltriethoxysilane. Data showing that the relative AP values after UV irradiationare greater for the multifunctional coating than for the coating formedfrom octyltriethoxy silane can be seen in Table 5.

TABLE 5 Antioxidative Power Before and After UV Irradiation. Before UVAfter UV AP t_(r) w_(c) AP t_(r) w_(c) (AU) (min) (mg) (AU) (min) (mg)Ascorbic acid 0.05% in: Placebo 550 0.24 2.51 45 0.24 30.99 ZnO 338 0.244.08 136 0.24 10.15 Octyltrieth oxysilane ZnO 348 0.24 3.96 288 0.246.31 Multifunctional Tocopherol 0.5% in: Placebo 103 0.30 12.09 0 — —ZnO 123 0.30 8.99 22 0.48 31.94 Octyltrieth oxysilane ZnO 270 0.30 3.7494 0.30 19.47 Multifunctional Green tea 0.05% in: Placebo 423 0.37 2.1010 0.53 28.33 ZnO 419 0.37 2.13 16 0.82 25.27 Octyltrieth oxysilane ZnO252 0.37 3.55 54 0.42 14.98 Multifunctional Hydroxytyrosol 0.05% in:Placebo 602 0.16 3.44 255 0.22 5.888 ZnO 549 0.17 3.54 281 0.22 5.36Octyltrieth oxysilane ZnO 600 0.17 3.24 545 0.16 4.55 MultifunctionalQuercetin 0.1% in: Placebo 395 0.54 1.55 291 0.54 2.26 ZnO 378 0.54 1.62221 0.53 2.82 Octyltrieth oxysilane ZnO 396 0.54 1.55 280 0.52 2.27Multifunctional

Example 4

This Example illustrates a coated nanocrystalline TiO₂ powder. Thecoated powder is the coated powder (i) from Table 1. The coated powder,in terms of weight percent, contains 92.7% TiO₂, 4.7% SiO₂ frompropylsilane moieties, 0.149% SiO₂ from silicate moieties, and 2.5% SiO₂from polydimethylsiloxane. The ΔE of this sample was 14.4 according tothe photostability test. Using an assay, such as X-ray fluorescence(XRF), Inductively Coupled Plasma Spectroscopy (ICP), etc., it ispossible to determine the weight percentage of each component of theignited powder. Using the ratio of the formula weights of the reactantsand the formula weight of SiO₂, the amount of weight lost duringignition can be calculated.

Example 5: (Prophetic)

This Example illustrates a coated nanocrystalline ZnO powder.Nanocrystalline ZnO (specific surface area=17 m²/g, correspondingaverage particle size=63 nm) is coated by propylsilane moieties,silicate moieties, and polydimethylsiloxane moieties. The ZnO particlesare coated by the moieties in the same relative proportions as inExample 4. The mixture is homogenized for 30 seconds and thentransferred to a glass container which is subsequently sealed. Thesealed container is then transferred to an oven where it is heated to atemperature of 100-110° C. and held for 1.5 hours. The resultant coatedpowder is then dried by unsealing the container and returning thecontainer to the same oven where it is held at a temperature of 100-110°C. for 1.5 hours. The resultant coated powder is highly hydrophobic andis super-photostable. The coated powder of this example andcorresponding dispersions are suitable for use in cosmetic sunscreenformulations.

Example 6: (Prophetic)

This example illustrates a high solids dispersion of the coated powdersthat is suitable for addition to cosmetic formulations. 460 g ofethylhexyl benzoate (Finsolv® EB; Innospec) and 40 g of an emulsifierare added to a jacketed steel container which is maintained at aconstant temperature of 30° C. The emulsifier, tricereareth-4 phosphate(Hostaphat KW 340 D; Clariant) is a waxy solid, anionic 0/W emulsifierdesigned to be used in formulations requiring some level of viscositysuch as cream preparations. The contents of the vessel are pre-mixedusing a Cowels saw-tooth high shear impeller under mild mixingconditions for 5 minutes until the mixture is homogeneous. In theconfiguration used in this example, the impeller blade diameter is ⅓ ofthe vessel diameter and is placed 1 blade diameter from the bottom ofthe vessel. 500 g of the coated TiO₂ powder of Example 4 is added to theliquid contents under mild mixing until all the powder is wetted. Themixer speed is then increased to 2500 rpm for 15 minutes. The resultantdispersion is pourable.

Example 7: (Prophetic)

This Example illustrates a water-in-oil emulsion cosmetic sunscreenpreparation containing only inorganic UV screening agents. The followingoil-phase ingredients are added to a heated vessel and mixed at lowintensity at 80° C. until clear.

TABLE 6 Emulsion Ingredients Ingredients Parts by Weight Emulsifier(Abil EM-90: Bis-PEG/PPG Dimethicone, 5.0 Cyclopentasiloxane;Evonik-Goldschmidt GmbH) 2-Ethylhexyl Palmitate (CAS# 29806-73-3,Crodamol 11.0 OP; Croda Ltd.) Decamethylcyclopentasiloxane (245 SiliconeOil; 7.5 Dow Corning) Cetyl Dimethicone (Abil Wax 9801; Evonik- 3.0Goldschmidt GmbH) White Mineral Oil (Carnation Oil; Sonneborn) 2.0Emollient White Ceresine Wax (Ceresine Sp-252; 1.0 Strahl & Pitsch)Emollient (Castorwax MP70 Hydrogenated Castor Oil; 0.5 Vertellus)

The oil-phase mixture is then cooled to 60° C. and mixed with the coatedTiO₂ powder of Example 4 (12.0 parts by weight) and subsequently passedthrough a high shear mixer until the mixture is homogeneous. Thismixture is then cooled to 45° C.

The following water-phase ingredients are combined in a separate vessel.

TABLE 7 Water-phase Ingredients Ingredients Parts by Weight Deionizedwater 56.5 Preservative (Germaben II; ISP) 1.0 Sodium Chloride 0.5

The homogenized oil-phase mixture and the water phase mixture are mixeduntil a homogeneous emulsion is formed. Note that optional fragrance(0.2 parts by weight) may be substituted for the equivalent amount ofdeionized water.

Example 8: (Prophetic)

This example illustrates a composition comprising the coated powder ofExample 5 and an antioxidant, such as hydroxytyrosol. 0.05%hydroxytyrosol is combined with 2.5% ZnO. This composition maintains agreater level of AP because the coated powder blocks UV radiation fromoxidizing the antioxidants, while the antioxidants increase thephotostability of the composition.

Example 9: (Prophetic)

This example illustrates a composition comprising the coated powder ofExample 4 and tocopherol. This composition maintains a greater level ofAP because the coated powder blocks UV radiation from oxidizing theantioxidants, while the antioxidants increase the photostability of thecomposition.

Example 10: (Prophetic)

This example illustrates an example of a UV curable coating compositionof the present invention. The following ingredients are mixed untilhomogeneous.

TABLE 8 Ingredients for Composition Ingredients Parts by WeightBisphenol A epoxy acrylate 80% in 44.0 neopentylglycolpropoxylatediacrylate Propoxylated neopentyl glycol diacrylate 30.9Ditrimethylolpropane tetraacrylate 3.2 Benzophenone 6.0 Acrylated aminesynergist (Chivacure OPD; 9.9 Campbell and Co.) Photoinitiator (Irgacure184; BASF) 2.0 Rheology modifier (Bentone 27; Elementis 0.4 Specialties)Coated ZnO nanopowder of Example 5 3.6

The composition of this example can be applied as a wet film to asubstrate using a wire-wound rod or spray gun and subsequently curedusing UV radiation to yield a UV protective hardcoat.

Example 11

This example illustrates a composition comprising effects pigments. Theeffects pigments are typically plate or plate-like pigment particlescoated with thin layers of a secondary material with a higher refractiveindex. The compositions of the underlying plates are typically mica,synthetic mica, silica, or alumina. The coatings are typically titaniumdioxide (typically anatase form), iron oxide, and bismuth oxychloride.

TABLE 9 Effect Pigment Uncoated Coated ΔE Std. Dev. ΔE Std. Dev. t-TestWhite Effect Pigment 4.85 1.68 0.39 0.11 5.30 Green Effect Pigment 2.971.41 0.42 0.22 3.57

The test was run at a concentration of 0.125 wt % effect pigment in asolution of 0.125 wt % DPPH in butoxy ethanol. The samples wereirradiated at 0.35 W/m² UVA radiation for 20 minutes. Four duplicates ofeach sample were prepared. D-50 is measured in microns. In Table 9, theΔE is significant when the t-test is 1.53 or greater.

TABLE 10 Effect Pigment Size Uncoated Coated White Effect Green EffectWhite Effect Green Effect Pigment Pigment Pigment Pigment D-50 Number15.45 14.13 16.30 14.62 Volume 21.67 15.67 23.13 16.17

REFERENCES

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1. A coated powder, comprising: (a) particles, and (b) a coating, on thesurface of the particles, including (1) silica moieties, (2) organooxysilane moieties selected from the group consisting of mono-organooxysilane moieties, bi-organo oxysilane moieties and tri-organooxysilane moieties, and (3) poly(dialkyl)siloxane moieties, wherein theamount by weight in SiO₂ equivalents of the organo oxysilane moietiesand the silica moieties is at least 0.0625% of the total coated powderweight per m²/g of the specific surface area of the particle to becoated.
 2. A dispersion, comprising: (1) the coated powder of claim 1,(2) a fluid, and (3) optionally an antioxidant.
 3. The dispersion ofclaim 2, comprising the antioxidant.
 4. The dispersion of claim 3,wherein the antioxidant is selected from the group consisting ofvitamins, antioxidant minerals, antioxidant proteins, antioxidantenzymes and coenzymes, phytonutrients and antioxidant hormones.
 5. Thedispersion of claim 3, wherein the antioxidant is selected from thegroup consisting of ascorbic acid, tocopherol, green tea extract,hydroxytyrosol and quercetin dehydrate.
 6. (canceled)
 7. The coatedpowder of claim 1, wherein the particles comprise at least one oxideselected from the group consisting of ZnO, TiO₂ and mixtures thereof. 8.(canceled)
 9. (canceled)
 10. The coated powder of claim 1, wherein theorgano oxysilane moieties each have the formula R¹ _(n)SiO_(4-n), withn=1, 2 or 3, and each R¹ group is independently selected from the groupconsisting of alkyl, alkenyl, alkynyl, aryl and heterocyclic radical.11. (canceled)
 12. (canceled)
 13. The coated powder of claim 1, whereinthe poly(dialkyl) siloxane moieties each have the formula O(SiR² ₂)(R²₂SiO)_(n)(SiR² ₂)O or O(SiR² ₂)(R² ₂SiO)_(n)(SiR² ₂)OR^(c), where n isan integer of 2 to 14, each R² group is an alkyl, and R^(c) is selectedfrom the group consisting of H, methyl, ethyl and propyl.
 14. (canceled)15. (canceled)
 16. A process for producing a coated powder, comprisingcoating particles with a polymer, by polymerizing a composition,comprising (i) the particles, (ii) a first alkoxy silane selected fromthe group consisting of a tetra-alkoxy silane, a poly(tetra-alkoxysilane) and mixtures thereof, (iii) an organo alkoxysilane selected fromthe group consisting of mono-organo alkoxysilane, bi-organoalkoxysilane, tri-organo alkoxysilane and mixtures thereof, and (iv) asecond alkoxy silane selected from the group consisting of apoly(dialkyl)siloxane and mixtures thereof, wherein the amount by weightin SiO₂ equivalents of the organo oxysilane moieties and the silicamoieties is at least 0.0625% of the total coated powder weight per m²/gof the specific surface area of the particle to be coated. 17-35.(canceled)
 36. A water-in-oil or oil-in-water emulsion, comprising thecoated powder of claim 1, and a liquid carrier. 37-44. (canceled) 45.The dispersion of claim 2, further comprising a dispersing aid.
 46. Thedispersion of claim 45, wherein the dispersing aid is selected from thegroup consisting of stearic acid, stearates, palmitic acid, palmitates,oleic acid, oleates, polyhydroxy stearic acid, phosphate esters, linearalkyl substituted amines, triglycerol esters, polyethylene glycerolesters and mixtures thereof.
 47. (canceled)
 48. (canceled)
 49. A coatedpowder comprising: (a) particles, and (b) a coating, on the surface ofthe particles, including (1) silica moieties, (2) organo oxysilanemoieties selected from the group consisting of mono-organo oxysilanemoieties, bi-organo oxysilane moieties and tri-organo oxysilanemoieties, and (3) poly(dialkyl)siloxane moieties, wherein the coatedpowder is super-photostable. 50-53. (canceled)
 54. A method ofprotecting keratinous material comprising coating the keratinousmaterial with a composition comprising the coated powder of claim
 1. 55.A method of protecting human skin, comprising coating skin with acomposition comprising the coated powder of claim
 1. 56. A method ofsuppressing lipid peroxidation comprising applying to the skin acomposition comprising the coated powder of claim
 1. 57. A method ofpreventing or reducing lines and wrinkles on the skin comprisingapplying to the skin a composition comprising the coated powder ofclaim
 1. 58. A method of preventing loss of elasticity of the skincomprising applying to the skin a composition comprising the coatedpowder of claim
 1. 59. A method of preventing thinning of the skincomprising applying to the skin a composition comprising the coatedpowder of claim
 1. 60-63. (canceled)
 64. A method of protectingantioxidants, comprising mixing an antioxidant with the coated powder ofclaim
 1. 65-90. (canceled)